Let's have, for example, the following phrase.
To create fancy product will require more effort.
Is it a grammatically complete and correct sentence?
Technically, the structure is actually "To verb-phrase will verb", and yes, it's a perfectly valid structure, although it can sound a bit stilted. In your particular example, you almost certainly need an "a" before "fancy product", though.
Also, it's probably more common (and definitely sounds less stilted) to use a gerund phrase rather than an infinitive-to phrase, thus:
Creating a fancy product will require more effort.
It is a sentence because there are subject ("to create fancy product") and a predicate that refers to the subject ("will require"), and it ends with a period.