Start by reading https://sourceforge.net/p/vms-ports/wiki/VMSHardware/
This will give you some idea of how much work you want to take on why certain models are cheaper than others.
The major problem with all VAX hardware is finding hard disks that work on them.
For most models though, you can VMScluster them over Ethernet from a a SimH system.
Cost can range from 0 to thousands of dollars depending on your luck.
You may want to post your location here and on comp.os.vms in case someone nearby is clearing out their stuff.
Stuff from e-bay or other online sellers is the cheapest route if you need to buy, but the cheap stuff may not work and need repair.
Because VAX systems are used in embedded controls for manufacturing, many companies will keep replacing exact parts on a obsolete VAX, even though it would cost them thousands less to upgrade to a more current VMS system.
This actually results in some very bizarre pricing on the open market.
At one time, a MicroVAX I CPU/memory set was selling for 2x what the MicroVAX II replacement parts were selling for.
My current issue is most machines I have run Windows, and I haven't been able to compile SimH myself on Windows yet so I do not have any sort of networking. Would a Raspberry Pi 3 be a good machine to run SimH on?
malmberg March 24 2018 Probably. More people hang out on the comp.os.vms newsgroup.
vaxpert March 23 2018 I have a PE42A and other Alpha system stuff for sale. I'm in So California. Any interest out there?
goodbyespy February 27 2018 To Prohorenko. Please, visit group OpenVMS in the ok.ru
peteherrera February 24 2018 How much does it cost to buy a complete OpenVMS hardcopy documentation set of the latest version
prohorenko February 17 2018 Please help to obtain the license on OpenVMS
malmberg December 12 2017 HPE only makes the most current version of OpenVMS Alpha / IA64 /VAX available to hobbyists. When I had access to the Alliance 1 program it was the same. No public downloads are allowed by HPE.
nmbonao December 08 2017 Is anybody knows OpenVMS 8.2 version downloadable version? or CD copy? Thank you very much
aarommes December 02 2017 Bitcoin and Blockchain enthusiasts ( plus distributed computing ) please connec / reply: http://www.openvmshobbyis t.com/forum/viewthread.ph p?forum_id=130&thread_id= 2991
malmberg September 10 2017 https://sourceforge.net/p /vms-ports/wiki/VMSInstal lation/ For the most part just use VMS 6.1 media instead of 7.3. But why run the older release?
DoeveR August 07 2017 Where can I find the write up on running VMS 6.1 using the simh emulator?
Bart March 20 2017 Happy to have found my password again!