Hope all are well...
Been down on the Eurostar/TGV for two years and it's a great way to do it... Last year (and we were a little late in booking... mid May) was £125 therebouts... From home (Bedford) to Le Mans took 5 hours therabouts... I'll be booking when tickets for Thurday departure become available and my guess is that it'll be c£90-£100.
Upsides for me... ? Not having to get up at 5.00am knowing you've got at least 10 hours driving you know you're knackered before you even turn the key... beers and food on the trains, brief stop in Paris and a wander round in Montparnasse...and this year the added bonus of sitting next to the very nice lady who was masseur for the Drayson Racing Team, on the Le Mans to Paris TGV...