Do you live in Wales now? My former finance was from Cardiff and he was still continuing to have difficulties because the building housing his birth certificate burned down years ago.
The vacations I've taken to Wales and contacts made have greatly improved my ability to find the right information with minimal effort. My two oldest sons will be headed back to college in the fall, so they have eliminated any financial resources for a vacation this year too.
If you can't afford to make the trip to the National Library in Aberyswyth, there are many reputable geneologists who can perform specific research on your behalf at the library. My friends in Cwmystwyth arranged quite a nice surprise on one of our visits. They located the actual paper document that transferred parental custody of my great grandfather and his two sisters to their uncle in Llanfihangel y Creuddyn in 1851. That document became a lead that showed that most of the family had come from that village. I had been on a few "wild goose chases" in adjacent villages with no prior success. Many of the original documents are archived in Aberystwyth. The many chapels around the country have consolidated their individual records at the national archive.