Shelf price or unit price?

Unit price, unless of course you wouldn’t use a larger amount in a reasonable time.  But there are sometimes surprises.  For instance, the store where I shop has two sizes of Cheerios.  Prices change frequently, and the small box is usually (but not always!) cheaper than the large box.  However, at least 75% of the time, the small box is less per ounce than the large one.  Last night I bought some vanilla extract, and the same thing was true: the small bottle was less per ounce than the large one.

Refinance or invest?

I (38m) landed a much better paying job a year ago and my wife (40f) and I should have about $50k saved by the end of the year and would like to solicit advice on what may be the best option for us. A little bit about me:Currently making about $120k. Wife works P/T making about $10k.
We have renters that bring us $700/month.
Only about $26k in 40k. Contributing 3% currently but will be upping that to 6% (company match).
Planning on opening Roth IRA’s for the both of us in the next few months.
2.5 years out of bankruptcy.
Current credit about 700.

Currently have a home 4 years into a 30 year FHA loan at 4.75% via streamline refi last year. Home is valued at about $360k, my loan amount is currently $291k, so I should be able to get rid of my PMI ($263) in about a year. Monthly mortgage is $2150

Something we have been thinking about is putting the $50k down on a 15 year conventional refi (talked to mortgage company and I qualify) which would get our mortgage payments down, allow us to pay off the home quicker, and save on interest paid. Even thought of borrowing $20k from parents do be able to put more money down on a refi due to the currently low rates (2.75-3%). We would be able to pay them back with interest in under a year. One major reason for this route is because job security is never a definite. One day, I could very well lose my job and end up finding a job that pays less. Paying off the home as soon as we can is something we’ve considered. If we are aggressive, we may be able to do this within the next 10 years. Even if we do eventually move from here, we would like to keep this home to provide us rental income.

After talking to a real estate agent relative, they were against the idea of a 15 year refi and recommended staying in a 30 year loan saying that the tax implications would benefit us in the long term. Maybe I’m not understanding this properly but my thought is that the money I’d save on interest would be far more than what I would save on tax deductions or other tax reasons. They also suggested possibly buying a cheaper property with this $50k, such as a condo, and renting it out. I’m not sure I’d be able to afford both homes (upkeep, no renter, etc) though.

Taking this $50k and investing is also an option. I’m a total financial dummy and will need a lot of guidance if I decide to go this route.

I’ve lived as a financial dummy and know I am late to the game. The goal is to be to be able to move to a better home within the next 5-10 years, be able to help our parents out when they’re retired, and plan for financial stability when we are retirement age. I’ve learned a ton from here and would love to hear, good or bad, what you guys may have to say about my situation.

Thanks in advance.