If the company that quoted you the $820 price includes FULL service, which includes full consultation, template, design, cut-in service (may entail an additional cost for cut), I would do it. You get invaluable experience that you don't get online. I would also let them do the first remove/clean/replace, so you can understand how YOUR system works.
After, I think you should do your own maintenance. When you have them do your system, make sure to keep track of ALL the parameters of the system (density, color, front hairline contour, base, etc). Also make sure you can get your template back (super important, it's yours, you paid for it).
If you are satisfied with your system, and how it looks, I would then consider buying a less expensive system (online, for example).
Doing all of this by yourself is not impossible, but how much is it worth saving a couple of hundred bucks if you get your first system, and you can't find someone to do the haircut? Or it's wrong? Etc.
$820 for a good system, from a reputable company, is not an outrageous price, nor is the $95 touch up.