Morning all, I've been a software/web developer for over 30 years so should probably add some of my thoughts/suggestions to this...
Current system - As someone mentioned above, at first glance it does appear to be a closed book, in that you don't seem to be able to migrate the whole thing to a different web hosting company. At the figures suggested above it also seems expensive. As a comparison, unlimited web hosting charge £50 for the year for a package with 99.9% up-time and unlimited data storage. Cheaper packages are available elsewhere but limit the amount of data you can store, which could become a problem very quickly with a site this size. Key is to find someone that doesn't limit the data, and provides regular back-ups.
Data migration - Providing you have access to the database (probably via phpmyadmin) then its not impossible to migrate to a different platform. Unless there is a tool that will migrate the data to a different platform for you however, it could take days, weeks to manually move all this over. This would mean locking the current system down while the migration takes place, otherwise your forever playing catch-up with new posts, threads, users etc. Obviously not ideal. Someone else suggested outsourcing the data migration, which is a good idea but likely to come at significant cost.
New forum - Personally, I'd take a look at phpBB. It's free open-source forum software, with good community based support. If you google football forums using phpBB, you'll see quite a few, including Man City, Arsenal, Bayern Munich, and (dare I say) stagsnet, to name a few. It's also most likely that some web hosting companies offer this installation as part of their package.
Domain name - you could ask the current owner to have this transferred to you, then all the dns entries will need changing to point to the new system. This should be the VERY LAST THING to be done however, else everything will stop working. Alternatively, someone like 123reg will sell you a new domain name for around £12 a year (currently 79p for the first year). So you could register for example bobsboard.co.uk , then move the other one over later so they both point to the same site.
Mods - As goku said, definitely needed.
So my suggestion for the easiest/ cheapest (£62 per year) option would be to :
- Buy some cheap reliable web hosting and a new domain name.
- Install phpBB as a new forum and run the 2 forums in tandem for a few weeks to give people time to register on the new one and start using it.
- Freeze this one and get a database extract, and see if we can get someone to try and migrate it as an archived forum /sub-domain on the new site.
Just my thoughts, and apologies for the lengthy post