How much is the basic 20yr option now? I initially got the 5yr visa for about $20k-$25k and then upgraded to the 20yr option for another $20k-$25k. Very happy so far.
Definitely not a scam. Mine costs about ฿900 per week for over 20yrs of hassle free living in Thailand. Easy extensions, easy to open bank accounts, depending on your location the extensions are a breeze, no need to leave Thailand, no need for re-entry permits etc, many other perks but mostly I like the security of the visa.
Expat groups are mostly what you mentioned. Many just looking to argue etc, even if they'd agree with you in person they'll find something to carry on about online. Is what it is, don't let it get under your skin.
Clinic will likely be cheaper than the hospitals here, the private hospitals that is, although the private hospitals do have packages which save a little but not a great deal but definitely cheaper than in Australia. My daughter has had all her shots (about 16 so far) from Bangkok Hospital here in CM.