That's what I did in September. I've always had a soft spot for spider varients and the 570s ticked all the boxes, it's an amazing car. I looked at both the GT and Spider, but trumped up the extra cash for the Spider.I tested the 570 convertible and the 720s yesterday, with the wife. Have to say the 570s was by some margin my favourite...certainly powerful enough and stratospheric compared to the Emira...cockpit is also a class apart. No shakes or rattles, a wonderful place to be and all round usability. 720 seemed slightly quicker from the off, and encourages you to drive faster, but without the fun factor....almost benign. I am now seriously tempted to request deposit back and go shopping...Given the time of year and state of the economy right now I am thinking there will be some bargains to be had...I am genuinely intrigued to understand the offer you have been given...I know from talking to our Mc dealer that they are willing to drop the price a little from the sticker value but am yet to push the button for a hard negotiation.
The best discount you will get will be via a private seller. I bought mine through GVE London. If you want further info about what to look for then PM me.