Price alone is not a reason to complain to either RECC or MCS as far as I know.

What would be interesting to know is:

1. What kind of projected generation and returns where your parents given.
2. Were they given the proper cooling of period.
3. Were they put under any sales pressure.
4. Did they “sign on the night” and if so were they offered any large discounts.

The RECC Code of Conduct does not allow its members to:

Stay in a house longer than necessary.
Offer you a discount to sign on the day
Claim there is a limited availability of a product
Offer a high price followed by a large discount
Withhold price information till the end of the call.