I haven't uploaded in full resolution and don't see a way to reload already loaded pictures in higher resolution which would be needed for print in 24x36"!!
Before the market was launched there was no reason to upload in higher resolution than 900pixels wide.
But since the market was launched I have got a number of messages about somebody who wanted to buy, but at $2.99 for a download why should I bother?
The message did not say if it was a print or a download.
Hence my pension blues!
If I had some musical ability I'd write a song to fit that title and
lose another fortune watching it go for free or, worse, an insulting, token, derisory laugh (at my expense).