He doesn't have anything he wants and if he did it would be so expensive I wouldn't be able to afford it.
"彼は欲しいものがないしあっても高価で買えない"
- He doesn't have anything he wants and if he did it would be so expensive I wouldn't be able to afford it.
- He doesn't want anything and if he did I wouldn't be able to afford it.
- There isn't anything he wants! If he did, it would be so expensive I wouldn't be able to buy it.
「彼はあまり欲しいものがないし、あったとしても車とか高価なものなので買えません」
- There aren't many things that he wants, and if he does its like a car or something expensive like that so I cannot afford it.
He doesn't really want anything, and even if he does, it's something expensive like a car, which I can't afford.
「彼は欲しいものがないし、あっても高価で買えない」というニュアンスは、英語では
・He doesn't really want anything, and even if he does, it's something expensive like a car, which I can't afford.
と表現できます。
"Doesn't really want anything" は「あまり欲しいものがない」という意味で、"even if he does" は「たとえあっても」の意味になります。"Something expensive like a car" は「車のような高価なもの」を指しており、"I can't afford" は「買えない」という意味です。
アメリカ合衆国 
