Unless you're changing fields altogether, or living in another job market where the cost of living is significantly different, you should almost NEVER take a pay cut. If the job is more hands-on engineering than this one, even at entry-level, that in and of itself makes it worth the higher compensation than an entry level position doing what you've been doing for almost three years. You should not expect anything less than something in the $48-50K range, given your current salary and experience level.