The announcement of an auction of more than 2000 postcards depicting Grimsby in its Victorian heyday brings into sharp focus the importance of photography as a collecting medium.

They come from a collection of 16,000 postcards amassed by the late David Robinson, editor of Lincolnshire Life and an historian, who died last year aged 89.

Each one is an historical document in its own right, packed with detail about how our forebears lived their lives and, from a market point of view, highly saleable because of their appeal to so many different people, from those who live in the area to local historians and collectors of vernacular photography.

As inexpensive items, they also act as one of the gateway collectables that trigger the desire to explore other fields of collecting, from grander, more expensive photographs to fine art in the form of prints, drawings and, eventually, paintings as individuals become more confident in their knowledge and so happier to spend larger sums.

The big story behind the Grimsby scenes is just how different the town is today. Gone are the fishing fleets crowding the docks; gone too are the trams gliding up Victoria Street. And, of course, the shops, clothes and buildings are largely changed too. I could sit and look at these for hours.

Another auction record has fallen in the past week or so after Christie’s brought the hammer down on $800 million (£590m) worth of art from a single collection. No surprise that the collection belonged to Peggy and David Rockefeller, a family that has been a cornerstone of the art market ever since wealthy US industrialists first turned their attention to culture towards the end of the 19th century.

To put in context just how big this sale was, the previous record for a single-owner collection was set by the Yves St Laurent Collection, also offered by Christie’s, which totalled $484m (£357m) in Paris in 2009.

The three-day Rockefeller sale ended on May 10 with a flourish, when a Picasso painting once owned by the writer Gertrude Stein took $115m (£85m) by itself.

By that time bidders had had the chance to compete for works by Monet ($84m/£62m) and Matisse ($80.8m/£59.7m) – a new record for the artist – while even those without access to millions could compete for modestly priced items, such as cufflinks.

All of the 893 lots offered live sold, with another 600 sold online.

Peggy Rockefeller died in 1996 and David in 2017, and the sale was staged by their son David Jr who pledged the proceeds to charity.

Great art, great wealth, a spectacular occasion and, at the end of it all, a massive boost to worthy causes; it doesn’t get better than that.

I have long been curious to find out what the most popular items are that people search for online when it comes to art, antiques and collectables auctions. Now, one of the world’s largest specialist search engines for this sort of thing, Barnebys, has revealed all in its latest annual report, which is being published in the next few weeks.

Looking at the registered search terms for auction alerts – when users set up automatic emails to let them know them that something they are particularly interested in is coming up for auction – it transpires that the most quoted brand name is Rolex. No surprise there, I suppose, nor that leading brand names for watches dominate searches in general, even though most people can’t afford them.

If so, why are so many seeking them out at online auctions? Is it just aspirational? Do they just want to inspect these watches close up and in detail? Or are they hoping to get a bargain? Who can say?

Whatever those reasons are, they must be the same for explaining the other most commonly used brand names in auction alert searches: Picasso, Banksy, Ferrari, Cartier and Tiffany.

All I can say is that I am just as aspirational as these would-be buyers. If I could fill my auctions with all of the above I would be a happy man indeed!

I have written before about the importance of association to the value of objects coming up for auction. Royalty and celebrity associations are perhaps the most obvious; music and sport are others. The appearance of a postcard on the market in Kent in the past week has reminded me of another: notoriety.

The postcard in question is alleged to have been written and sent by Jack The Ripper, the Whitechapel serial killer who struck viciously at the end of the 1880s, killing five women in a matter of about ten weeks before disappearing, never to be heard of again.

There have been other murderers, but none has captured the public’s imagination like Jack, so interest in anything associated with him is inevitable among some collectors, especially those who retain hopes of unmasking him, none more so than the crime writer Patricia Cornwell, who has spent several million pounds, concluding that the guilty party was the well-known painter Walter Sickert.

The postcard now up for sale, sent to the police station Ealing on October 28, 1888, promises to kill two unnamed women and arrived at its destination 11 days before the murder of Mary Kelly.

With an estimate of £600-900, it clearly has a great deal more value than an ordinary postcard of the era. If any doubt about the Ripper’s authorship could be removed, I suspect you could add another zero to the price.