The S&W 686 model ...is certainly moderately priced / way less than a Colt - and a good solid long term gun - especially as a shooter.
I would at least recommend you also look at K frame S&W's ...like the model 66 ....or even an N frame like a model 27 or 28. The model 27's will rival the Colt Python, in my opinion, and are more affordable. The model 28 is a satin finish version of the model 27 and more affordable if you like that look.
In general....a 4" barrel on a K or L or N frame revolver...makes a nice defensive gun / easy to draw from a holster...../ where the 6" is a little tougher to get out of a holster ( but maybe better for a night stand gun / or a range gun - with the longer sight plane).
I'd suggest you go to a range and fire K and L (686) and N frame S&W's in both 4" and 6" ...so you can evaluate the size and feel of each - and pick what you like the best.
Colt Phython is a very nice gun ...but I personally like the triggers on the S&W's better ...and I'll take a really nice S&W model 27 over a Python any day - the S&W's fit my hands better than the Python as well. But what matters is what fits your hands - not mine / and which gun you like esthetically better ! Have fun with the process...