How much is a patent, roughly, if I just want a ballpark?

As a ballpark: an initial priority filing costs a few thousand dollars all-in, a full utility patent through grant costs $10,000 to $20,000 in the US or a comparable amount in Europe, and keeping it in force for its full 20-year term adds several thousand more in maintenance or annual renewal fees. Budgeting for one country alone understates the real commitment: a full patent family protecting the same invention across key economies, typically the US, Europe, the UK, China and Japan, commonly runs $50,000 to well over $100,000 across its lifetime once PCT fees, translations, local attorneys and every country's renewal fees are included. Fee discounts for small businesses and individuals, such as US micro and small entity status or the EPO's micro-enterprise reductions, cut the government-fee portion significantly.