If you do a search on ebay for sold listings and type in "roamer alarm" you should get a sense of its value. Looks like 3 sold recently ranging from 23-105 USD. The 23 was a parts watch and 105 was gold plated. I think your was nice than than eBay so I think you paid a fair price.
I'm no expert in Roamer so I can't comment on the dial originality which will have an impact on value