Before rubbing your cheap tickets in the face of a co-worker, be sure to dig through the litany of potential fees. Spirit is a budget airline, so you're paying for "extras" such as seat selection and luggage. It can add up quickly. As you do so, note that Spirit's $9 Fare Club might make sense if you're packing a lot of luggage. The club is about $60 a year and gives you a handful of benefits including significant discounts on luggage, which could pay for itself in a single flight if you're traveling with a partner.
Alternatively, you could dig into Alaska Airlines' three-day sale with one-way fares for as little as $40, which includes a free carry-on, or WOW Air's sale with cheap flights to Iceland.
Nonetheless, even with fees, Spirit's sale could land you cheap tickets to somewhere way better than your office on a weekday.