I have three lenses of which none are worth more than $200. These are also the only ones I've ever used, so I don't have a lot of experience with lenses to compare.
Canon 18-55mm f/3.5-5.6
Canon 50mm f/1.8
Sigma 70-300mm f/4-5.6
90% of the shots I take are on a tripod, and of those, most of the time I use a remote shutter release, MLU, and stop down to about f/8.
My question is, given the way that I shoot, am I missing much compared to lenses such as Canon L lenses? Spending $1000 on a lens is a huge investment for me so I go back and forth on whether I should save to replace my current lenses or spend my money on other photographic equipment.
So to help me figure out where to spend my money, I guess I'm asking, would I see a significant difference in image quality by replacing my lenses?