Tyres for 2004 V6 Freelander?

Hi All,
I'm about to take the plunge and buy a 2004 V6 Sports Premium 3 door (gulp). The tyres are a bit low on tread and I'm after any advice on budgeting for replacements that won't break the bank too much. The car is mainly for week-end family fun and so only very mild off road use. The tyres fitted are 235/50 x 18.
Any advice or suggestions (other than "don't buy it"!) welcomed.
Thanks

Try
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get a warranty with it

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and a second job, just in case