Buying a bath entry ticket to any Budapest Thermal Baths is affordable, even if it is not cheap.
Although, there used to be a refund system in certain baths (for example Szechenyi Baths), but this refund system is no longer in use. If you purchase a full time ticket but only spend a couple of hours at the baths, you are not entitled to any refund.
Instead of the old system at Szechenyi Spa Baths, morning, afternoon,and evening tickets are available, as well as full day tickets. The ‘day section’ (i.e. morning, and evening) tickets allow you to stay for 2 hours, the full day ticket allows you to stay any time of the day for any hours, as long as the facilities are open.
Buying the full price ticket is definitely worth it, as the baths and pools, the massage therapies, etc. are really fun and time flies by quickly in any spa in Budapest.
There are also different ‘day section’ Bath Ticket types in every Baths in Budapest.