How would the cheaper 40mm lens line up ? Not really wanting to spend a ton right now as I'm buying the refurbished kit .. Trying to stay within my budget . I like the small size of the 40mm, any other small cheap options ?
I owned the 40mm on the same camera, and sold it. My thoughts:
* Felt cheap, and I was afraid it would break
* No IS
* The 28mm f/2.8 IS USM which I also owned was barely any larger, better quality images, image stabilization, more sturdy, and more useful focal length for crop cameras.
* While the focal length of 40mm is great for full frame camera, it is weird for a crop camera like the one you are buying. For crop you have to multiple the focal length by 1.6 to get the effective field of view, so a 40mm on crop looks like a 64mm on full frame. 64mm is far too long for indoors, yet a bit too short for portrait work. Thus it is not too useful on a crop camera like the one you are buying. You want to stay in the 24mm-35mm range for indoors work with a crop camera, with 28mm being the "normal" sweet spot as it nearly is identical to the sensor diagonal on a 1.6 crop like the one you are getting.
You could try to get a used 28mm f/2.8 non-IS lens, they go for relatively cheap - but it kind of defeats the purpose as the 18-135mm is probably better in image quality than such an old lens. The new 28mm f/2.8 IS version is worlds better in image quality, approaching the quality of $1000+ L-series lenses while being less than half the price.
I would not buy another lens just to buy a lens, you should really look at what would benefit you. Getting a 18-55mm duplicates the 18-135 and doesn't buy you any image quality or speed, and the 40mm is too awkward of a focal length for crop camera like you are buying. A lot of the cheaper lenses are just going to be quality compromises that will likely disappoint you in the long run.
If you cannot afford the 28mm IS USM and want another lens, how about the 55-250 STM? That would be extremely useful for outdoors/telephoto and it is only $349.00. That is one you will keep for a long time to come and not be disappointed in. It is brand new and has image quality that rivals the $1500 70-300L.
Then, when you have some cash saved up, grab the 28mm f/2.8 IS USM for a small lens for higher quality indoor photos.