Besides the obvious being art prints and books, I was think of other merchandise ideas that are affordable, but fun. I was thinking stickers and maybe even a colouring book. I was thinking of going in the kid friendly direction because my comic is cartoonish.
The way I see it, prime Webcomic Merch are:
And that's about it, though there have been other things! Tabletop games, for instance.
Axe cop even got Action Figures and a Rubie's Halloween costume. Now, I'm not saying Hyde won't make an awesome costume, but, even the Axe Cop costume seems like a huge financial risk. And that sounds condescending as hell.
For Jekyll and Hyde, I'd say T-Shirts, Stickers, and plush toys of Hyde and Stevenson (maybe Robert).
EDIT Forgot calendars. Probably because I've never been good at consistently marking them.
Sticker Mule is always doing sweet deals. I ordered 10 3X3 die cut stickers for $1 with shipping included. I even got 2 extra. I think they just had a deal on bumper stickers but keep an eye on them and you can grab some nice cheap merch from them.