So you had a second channel opened to you, because your first one didn't have enough capacity to receive the new amount you sent. By default, the just-in-time services gives you 100k sats of inbound on top of the amount you're looking to receive. Whenever a new channel needs to be opened, the required fee is displayed clearly above the invoice QR. If you want to be most economical, you can use the advanced channel service through the 'Purchase inbound channel' and specify the amount and duration you need so you can do long term planning. As far as costs VS custodial. Yes, custodial wallet charges less in fees, but that's at the cost of control of your funds.