Want to upgrade my lenses and other accessories.. Checked out canon
lenses which are too expensive.
"value for money" doesn't necessarily mean "inexpensive". If you don't believe me, there are some guys selling body caps with pinholes for $12 each over on ebay.
Canon offers a number of lenses that will take very good images and which are quite fast without breaking the bank. You don't say what kind of lenses you're looking for, though, or even what your budget is, so it's going to be pretty hard to be specific.
If you're looking for better quality and lower prices, you'll probably want to look at prime lenses (i.e. lenses with fixed focal length) because they have fewer elements, fewer moving parts, and are therefore simpler and less expensive to manufacture. People speak very well of Canon's EF 50mm f/1.8 II, which costs around $100. I've got a EF 50mm f/1.4, which costs more but is still pretty affordable, and I couldn't be happier with it. Canon also offers the incredibly compact EF 40mm f/2.8 STM for about $150 -- that might be a better choice for a general purpose fixed-length lens for your Rebel XSi as it'd be similar to a 65mm lens on a full frame camera, rather than the 80 mm that the 50 mm lens will appear as.
There are surely values to be found with other manufacturers as well, but the general theme will remain the same: prime lenses are generally faster, sharper, and cheaper than zooms.