I'm going to piggyback on what babystarz said and clarify something because although I do understand what they said, it might be misinterpreted... seen it a lot on this forum.
Getting a pair of bettas to spawn is not hard. Male + Female = eggs
Yes, there's a lot of preparation that goes in breeding but I think it's very important that newbies know that the easiest thing is to get your spawn to mate.
The hard part comes in raising fry to adults. There are a million things that can go wrong and the smallest mistep and you will loose all your fry.
It does take lots of time and money.
Time: you're looking at a couple of days of constant supervision of your pair in the spawn tank until they spaw.
Then once you have your fry; they will require 2-3 feedings a day of LIVE food which you have to culture and daily 50-100% water changes to get good growth on them.
Why it cn get expensive? There's specific equipment necesary for a spawn and live foods can get costly depending on what you decide to feed.
Quality brine shrimp eggs are not cheap plus they are a PITA to hatch.
Micro, banana, and walterworms will probably be the cheapest live food you will be able to get but your fry will outgrow them very fast.
If you decide to feed grindals, those cultures go from 15-30 dollars.
Once you have succesfully grown your fry to 2-3 months in your 20+ growout tank you will need to separate because they will get nippy with eachother. This means a separate container and heater (unless you go with a space heater) for each fish and daily water changes for each of those containers until your fish are ready to be rehomed.
So if you're comitted, it's a wonderful hobby.