Shouldnt be that expensive, the actually expensive stuff I noticed is block%. I got the rest quite cheap (9500 armor 950 AR 1200str 1000vit), not that it would be enough but I think you are looking for the wrong combinations if your upgrades are that expensive for you. For the dps you should add some more crit and/ or attack speed and crit dmg. I personally found out that it is the cheapest to buy pieces with like 60-70 AR and maybe one ring with AR, if you get some decent deals you should be able to easily get up to 900 AR.