It's an interesting approach, and I'm not unconvinced that the premise has some legs. At the same time, your target customer -- and your articulation of the value proposition for that customer -- seems a little unclear.

Who is your target customer, and what are their pain points re: art buying? And how does renting-before-buying solve for those pain points?

Let's assume casual or beginning collectors. You're asking them to pay up to $600 a year to rent a piece, so presumably, you're targetting people who are in the market for pieces at least in excess of that price tag. In which case, you're not yet in the super-serious collector segment -- but you're operating in what must still be the 90th percentile of all art buyers in the country.

On the higher end of the market, let's look at serious but not uber-rich collectors. What would they get out of this service? Potentially the following:

1) Provenance? Possibly, but only if you document every person who's rented, and probably only if those renters are respected collectors or institutions. Possibly a cool idea to be worked out on this dimension, but also a pitfall if you don't address it properly. I could see the rental concept's having a negative effect on provenance if not handled well.

2) Sampling / try-before-you-buy? Maybe. If a piece isn't selling for well north of $600 to begin with, the economics don't add up. You need customers who will be looking at the pieces as investments, and not necessarily as decorations. (In which case, I would suggest choosing different images and copy on your site to reflect such a mindset. The pics and copy on the site right now give off an art-as-decor kind of vibe).

My biggest critique is that you seem to be straddling a few lines between customer segments and use cases. I'm sure you have carefully considered exactly whom you're targeting and exactly what problem you're solving for that target. But it's not clear in the layout/UX of the site.