It's not really a lower-cost alternative due to cartridge prices and no sales.
I chose Steam Deck instead of the Switch. Yes the SD is more expensive, but it already supports most of my existing Steam library and I can buy new games on sale.
Do their first party games also get those discounts? Another thing is that I can play games that I bought 15 years ago on my Steam Deck. Nothing like that is possible on the Switch. Even if you owned, say, Mario Kart 8 on the Wii U - you have to rebuy it again on the Switch.
I chose Steam Deck instead of the Switch. Yes the SD is more expensive, but it already supports most of my existing Steam library and I can buy new games on sale.