I'm not sure if each line represents a different memory stick or if those are two different sticks or two stickers on the same stick. What I can tell you is that the memory that the first line belongs to (1Rx8 PC2-6400U-6612) is DDR2 800MHz Ram (as denoted by PC2-6400), and the memory that the last line belongs to (SNPXG700C/1G) is a 1GB stick (as denoted by 1G). You still need to find out if it is laptop or desktop memory (is it long or short) and it would be good to know the manufacturer or the brand of computer it comes from.
So if the first and last lines belong to the same memory then you have a 1GB stick of DDR2 800MHz memory, this is about as basic as you get when it comes to DDR2 memory and will be worth very little as a unit, however if all 50 sticks this way you may package them in groups to raise the potential selling price such as a 2GB set or 4 GB set, but no more than 4 as most computers can only hold 4 sticks.
Also, don't flood the market for yourself, if you put all 50 sticks on eBay the competition per stick will be very low, however, if you put one set of each type up at a time the competition will be higher per set and thus a higher selling price overall.
All told I would say if each stick is the same as what I presumed from above you have roughly $500-1000 worth of memory in your possesion.