Such a cool place to see, and you can always find bargains and lots of weird things you wouldn't find anywhere else - perfect for unique gifts!
Even if you don't buy anything, this is a great spot to go... being part of Riga since 1930, I got all kinds of warm fuzzy feelings being there surrounded by locals. I didn't buy much, but I did get postcards (of course) that were made by a local merchant (each was unique) and a couple of stamped pewter pieces clearly made for tourists, along with a couple of really unusual rocks that aren't in America--got those for a lapidary I know. Definitely go if you have a chance. The merchants were a little eager to get my business since of course I was perceived as rich (even though I took one of those 12 euro flights there and my total budget for 3 months of eating, traveling, etc. was $1300), but they also took my polite no thank yous with stride.
Really cool big open marketplace. Riga Central Market is worth seeing just as a tourist sight, but then of course you can always find some cheap shopping here as well - it's definitely worth checking out.