Several years ago we had a large garden with lots of lawn. We had a large ride on mower and it was excellent, but my husband who was very good at maintainace and repairs of most things did spend a lot of time cleaning it, sharpening the blades, and getting it going at the start of the lawn mowing season. I recently had my small mower serviced and blades sharpened which cost £45. A large flymo might be the answer, and as suggested do it yourself and note the time. I do remember once a month we spent a whole day doing the lawns, using both mowers and edging and deweeding. In between we just mowed and flymowed. They did look lovely when done.