Help! Do I invest in engineering or secure IP first?

Hello, I'll keep this brief, but looking for a little insight on a big decision (for me).

I'm stuck between A) paying an engineer ~$3,500 to design my V2 (he designed the first one) prototype PCB board for a hardware design or B) Secure a provisional patent.

I'm bootstrapping this and have a very limited budget, so the engineer would basically blow that up.