Welcome! You will get brilliant support here on the forum, both in current threads and the archives. You can search with keywords, it's a terrific function.
There are several discussions about eBay.
Seems to me you have several strikes in your favor.
First, Herat Oriental is nearby! This must be a truly magnificent resource, in terms of education, enjoyment, advice and purchase.
Secondly, you're already astute in terms of everything having its value, and that being accessible to nailing down.
I'm pretty new here too, and have found it a tremendous resource. You don't mention money, that is one of my principal limitations. Even that can be softened, however. Another thing I'll say is that interacting with members is broadening my taste!
Keeps us posted! I'll be looking forward to seeing that first baby! Hope you share the search with us too.
On eBay and Craigslist: In my experience and area, there are a lot more rugs on eBay. I have started to use eBay to look for sellers as much as rugs, i.e., I research the seller on toolhaus.org, also here in the forum, maybe buy something small or correspond. Now I have a list of sellers whose inventory I can browse. Of the 4 transactions I've had so far, two I would do business again with; one I wouldn't even look at their rugs, and one I would hesitate before buying from again.
You can also post photos here, before purchase, and ask for opinions; or use the rug valuation tool on rugrag.com, or get a full report for a small fee.
I like Craigslist a lot but, in my location, there are few rugs. But I like it because it is local, and gets me traveling all over my (very small) state, and brings me into contact with people, some of whom are craftsmen and artisans, and many of whom have interesting stories to tell!
My ideal buying scenario would probably be a warehouse rug store! I have two good rug stores in my area where I can go and faint, blissed out on color and the smell of wool. But the prices make me faint too, even though they are negotiable, and not really outlandish. I just don't have much disposable income.
Good luck in particular with your Kashan search; I am searching for a 9 X 12 medallion kashan, with a navy field, and good blues.
I have tried to get Kashan / Ardakan discussions going here without success! There is one old thread about kashans, you can find it by using the search function. In your kashan search, I will benefit from your questions and observations.