Try copy paste the code below as is.
if ($wpcs_display_cart == 'yes') { ?>
<div class="cart"><a class="add_to_cart_button btcarrossel" href="<?php the_permalink(); ?>" title="Comprar <?php the_title();?>">
Comprar
</a>
</div>
<?php } ?>
And sorry if I’m rude, but you should pay way more attention to your code. You have a parse error because you have html inside php without echo “”, and without the need to do so.
Try to spot the differences between the code above and the one you posted.
Edit: Sorry, the code i posted first was broken because I did not use de “code” wrap around it.
Did it work?
If you still get an error let me know which.