1. Black & White film development is relatively easy to DIY.
2. C41 (color) film development is more temp sensitive, so not as easy to DIY.
3. Scanning is troublesome to setup (and find the sweet spot in the config). But once you get the hang of it, the main cost is just time. Plustek 7600 and Epson 700 are the 2 default scanning solutions for 'prosumer' or amateur level who want a reasonable result.
The reason why I prefer to DIY scanning is because I have more control over the result. of course this is my personal generalisation.
Not sure what standard you expect. if you prepared to pay professional scanning using drum scanner, then good for you, that type is super high res.
for amateur-standard type scans on the cheap, so far the results I get from photolabs - well I rather do myself.
I am just giving the DIY amateur viewpoint, btw. got many sifu here can give u more profound tips.