I misread understood "collecting."
If you like the look of a shiny, black bit you will have to clean it now and then. Nothing serious. I polish the bit with tooth paste to remove the oxidation, shine it up with a bit of buffing paste and then a coat of Obsidian. I doubt I do this more than once a year with any one pipe. It can be done quickly and easily when you clean your pipes if you see that it is necessary. It's really not a chore, just something that needs to be done now and then.
I suggest your pipe rack or storage device not be in a place where it gets a lot of direct sunshine.
The beauty of pipe maintenance is that you can leisurely enjoy a bowl as you do the weekly cleaning chore. At least that is how I do it.
I do not buy used (estates?) pipes as a matter of personal preference. I do not buy a pipe I have not physically inspected so, I do not purchase on line. I no longer have a shop in my area (I envy those that do) and only purchase when in Ireland, England or Chicago. I have a couple of dozen pipes and do not feel the need to buy a new pipe, all of mine smoke well and 24 is a reasonable number to own. Again, my personal preference. This rotation took me 40 some years to gather. The majority of them have been with me for at least 20 years.
I think purchasing from any of the site sponsors is reasonably safe with regard to quality and support. Other members can vouch for the retailers through their dealings with them. If I was new to the diversion of the pipe I would use the search function on the site and enter a few of the retailer names. Most of the threads will reflect satisfaction.
You will, in your experiences, at some time come across a pipe with a shape, grain or finish that you really "must" own which will have a defect (fill, dent, etc.) or issue of some sort. With a bit of experience you will be able to "suck it up," make a reasonable offer and either live with the imperfection, have it repaired or learn to do it yourself.
My favorite Peterson suffered a small dent when a customer or clerk dropped it on the floor. Not a glaring imperfection to be sure but, still it was there. The shape, size, fit of the sterling lid and collar, etc. were impeccable. I made an offer and walked away with fairly expensive pipe for which I paid much less than retail. The wee dent adds an appealing bit of imperfection to an otherwise, in my eye, a perfect pipe.
Remember, there is a learning curve. Just getting the bowl filled correctly requires experiment and experience. Do not get frustrated and keep your eye on the goal. Embrace the failures and learn from them.