Repeating some things already said...
The first thing to know - but one of the hardest - is how much flying you are going to do. If you never owned a plane you are sure to overestimate this. 50 hours per annum is on the high side, generally speaking.
IF flying no more than that, the diesels will not be worth the higher cost for acquisition and maintenance. For their lower fuel cost they are much in demand at training organisations.
IF flying no more than 50 hours per annum, do consider a syndicate, especially if you are in a country where these are common, like the U.K.
IF cost is an important factor AND you like tinkering than consider getting an Annex II - you said microlights are not for you, but an antique or homebuilt could be ok. The cost of maintenance will be substantially lower, but all that tinkering will leave you still less time to go flying. Ask me how I know!