Ultegra is quite a high spec and as such will command a highish price. 12/30 is available in Tiagra that may sound like a downgrade but will do the job but I do believe that there is now an Ultegra 11/30 available.

11/32 is available in Shimano LX but you may require a long reach Rear Derailleur to be able to fit it.

Sram in the PG1070 range do an 11/32 and a 12/32 but may require the change of derailleur again.

In fact even going to a 30 on the cassette "May" require a longer reach rear Derailleur- depending on what your current one can handle so be prepared for that as an "Extra" expense.