、。
The budget seems inaccurate, and on top of that, unrealistic.
Literal
Budget [topic-は] inaccurate-[te-form-で], moreover, unrealistic-[adverbial-に] seem.
しかも ('moreover, what's more, on top of that') is an intensifying conjunction, adding weight to a negative observation. The te-form で here is the na-adjective copula in te-form ('is inaccurate and...'), chaining two characterizations of the subject. 思える is the spontaneous-potential form of 思う — 'seems, gives the impression.' Note the prefix 不~ ('un-, not') on 不正確 and 非~ ('un-, non-') on 非現実的: two different negative prefixes used with different word types.