ALB pricing is a little strange thanks to the $5.76/mo/LCU cost and the differentiation between new connections and active connections. The days are LONG GONE when AWS just charged you for "how much you use", and many of their new products (Dynamo, Aurora Serverless, ALB) are moving toward a crazy "compute unit" architecture five abstraction layers behind units that make sense.
But it should be cheaper; back of the napkin math, 225M req/month is about 100RPS averaged, which can be met with maybe 5 LCUs on an ALB. So total cost would be somewhere in the ballpark of $60/month, plus the cost of lambda which would probably be around $100/month.
Is it cheaper than a VPS? Hell no. Serverless never is. But is it worth it? Depends on your business.
The ALB point is very strong. APIGW can add lots of value with request response manipulation and the headaches of managing your own VPS, but you need to make sure that you don't just need a bare bones path -> lambda mapping, which is where the ALB can shine.