Per month?  I don't know anyone that has ever paid that much. 

Depends on location, number of lanes, number of league bowlers, amount of open play, size of shop.  Too many variables. 

Even in southern California and New York I've never heard of rates that high.  Maybe if it was a large center in an affluent area with huge open play and a lower league bowler count.   

If there are only 200 league bowlers and you are paying any rent you are paying too much.  January is typically one of the best months in the pro shop, so if you only worked on 20 balls last month the future doesn't look good.

I'm guessing by the way you worded it that you are paying 3/8 of gross revenue.  Most well run pro shops can keep their COG's around 50%, so I'm sure once all your expenses are figured you are losing money.

Unless you are only opening the shop one day a week I can't believe this venture is worth doing in a town of 25k with 2 bowling centers. 

If my math is correct, 182 times $1.50 = $273 per month. That is if the center is not counting the bowlers more than once if they bowl in multiple leagues,

I do not think that is too much.  You need to either sharpen you skills (no insult intended) or do a better job in marketing your business.  If you are new to the pro shop business, you are probably competing with other shops that have been around much longer than you. It is very hard for a bowler who is happy with his current shop to go to another shop. 

Yes, I agree that most centers like having a pro shop, but lets face it, in todays market, at least in my area, the centers are not making a ton of money.  Some of them are removing the shop and installing vending machines that contain tape etc. and using that space to install more video games.

If I were you, I would review my pricing and look for ways to better market my shop. 

OP said the following:  "I profited off the following last month: 12 balls, plugged and redrilled 7, baked 3, and sold about 50 inserts plus other accessories.."

Let's assume his prices are generally lower:

12 balls ($50 each after paying for the product) - $600.00
7 Plug & redrill ($30 each, not knowing what he actually plugged) - $210.00
3 baked balls - $45.00
50 grips and accessories - $200.00

Total $1050.00 roughly, minus rent $273.00 (if the math is right)  So basically with any other overhead he may have he's making about $150.00 per week.  I'm hoping this is not a full-time gig for you. 

(Obviously these are very rough numbers)

Google Columbus, MS.  It's a town of 24,000 people with a 15% unemployment rate and the median income for a household in the city was $27,393.  The bowling center is open 5 hours a day. 40 people bowling league per day.  The best marketer in the world couldn't make any money in a pro shop there. 

5000 is a good number to remember here.

That is the number of local league bowlers (within ~25 miles) that it takes to support 1 full time pro shop that wants to make a fair living.

Rent in this situation should be comped ball repairs and maybe donated time to coaching kids to try to build a base.  They should be happy to have you there.