How about custodial payment prcoessor/gateway such as https://www.coinpayments.net/? While you don't have control over the token, it's far cheaper than setting nodes/wallet for each altcoin.

I would honestly recommend using BTCPayServer, but it's Bitcoin-only.
[/quote]

There's community community modification to support some altcoin though, https://docs.btcpayserver.org/FAQ/Altcoin/#which-coins-does-btcpay-server-support.