Yes you have to buy a ticket to enter to the premises.

As previously mentioned, the Ushiku city hotel near Ushiku station should be the nearest and you can take a bus from the station to the Buddha. But I think the rooms are tiny, which is pretty much common in every hotel in the area. Hotel Bestland in Kenkyu-Gakuen, Tsukuba is nice but you definitely need a car to get to the Buddha. To be honest, 2 hours visit is enough for most people. I would stay in Tokyo and just have a short trip to the Buddha and an outlet mall. Or dropping by on the way to the Narita airport.

You could get on a train to Ushiku station and then you can take a bus at Ushiku station east exit bus stop number 2 bound to either "Ushiku daibutsu" or "ami premium outlet" takes about 20 to 30 minutes going by car is the best way though

Half day trip in total, do to JR Yamanote-line, switch on Nippori Station to Johan Line, then exit Ushiku. The take the bus there, 20 min ride (consider shedule). With lunch in Ushiku, a Frech Restaurant I can recommend, near the bus station, a nice trip.