A few years back, my 15 year old stepdaughter came to me with a request to participate in a field trip to a Shakespeare Festival for several days. They'd take a coach, stay in a hotel, and see 4 plays - some Shakespeare, some not. Most of her friends in drama club were going. The cost, I clearly remember, was $475. I couldn't really afford it. I'd just realized my house was underwater, there had been an expensive electrical fix. My car had just require new brakes. I'd made several risky/hopeful investments in rental property and a small business and wasn't yet reaping any benefits; I was in the hole each month, on top of pre-ACA health insurance premiums and Montessori for my toddler. I was skating by on my kids' Social Security and hadn't yet received the insurance money from my late husband's car wreck.
But I said yes. With no strings, no caveat about paying me back or earning half the money to "prove she really wanted it". She did want it, and she'd been so great and so helpful with the little kids, not really asking for much, so it seemed a small thing to hope for in this life.
And she loved it. For days/weeks afterward she talked about the plays, the writing, the actors and the bonding with her classmates. I juggled expenses for the next month or so, putting more on my credit card than I was comfortable with and felt the $475 (plus the $80 or so in cash I gave her for spending money) was well worth it. Several years later, when money was not so tight, I helped finance a semester abroad in Florence for her - this time she did come up with part of the money, and her grandmother, uncle and I all kicked in a not-inconsiderable amount that her otherwise full scholarship did not cover.
What's the deal with the $200? Either you say yes, or you say no. No games, no teachable moments. If you can afford it, and it's a worthwhile experience your son will benefit from, why not?