I like using essential oils but they're quite expensive to buy, even in small quantities, so I seldom buy them.
I really like essential oils but they're pricey for even a small bottle, so I hardly ever buy them.
「精油が好きだけど少量でも高いから滅多に買いません。」という言い方です。
1) I like using essential oils but they're quite expensive to buy, even in small quantities, so I seldom buy them.
2) I really like essential oils but they're pricey for even a small bottle, so I hardly ever buy them.
「精油」は essential oils
「少量でも」は even in small quantities や even a small bottle と言えます。
「滅多に買えない」は seldom buy ~ や hardly ever buy ~
ご参考になれば幸いです！
日本 
