i do the same, tho unfortunately my main problem is animals
its like im hypnotised - I get the urge/desire to have a dog, cat, mouse etc and the thought wont leave my head until I HAVE it, it takes over my mind all day, weeks, months. ive been obsessing over finding a rabbit lately and im trying to fight the urge but I know ill cave in. ive already had 3 
few years ago I had this idea I wanted to bake, so went on a crazy buying spree spending £200 on cake tins, trays, bowls and ingredients! I had every flour, sugar and spice you could need in my cupboard - but after all that I didn't want to use any of it. it just sat there.
another example is lego for my ds's. I had to order lego everyday, spent hours on ebay searching for the stuff! when it arrived It had to be washed, sorted and not touched because I knew I had some more coming so wasn't finished sorting!
I too am crap with decisions and choices, I normally buy multiple if I cant choose, like tops. id buy the same in different colours. my dd had 8 pairs of shoes at one point cos I couldn't decide which ones were best for her.
mentioned this to gp, psych and counsellor but they don't seem to think its an issue 