Just make sure the insurance company were aware that it was a jap import, as to me that quote seems very cheap for a 21 year old. Do just recheck your quote, so you don't get your hopes up.
Other than that, a supra would be a great buy, especially if you do so few miles. A word of warning though, if you've no rear wheel drive experience, Supra's can be tricky to drive and will catch you out, especially if you're acting the maggot and don't have much experience. If you do get one, just take care in it, as it will bite when you make a mistake.