It's obviously a very good investment - you are getting the hang of starbonds. She is priced so low because she had a recent adjust a couple of weeks ago, and it is a no-brainer that she will go up by a lot. The only down-side - for you - is that it would tie up over 10% of your port for the next two months.
In the meantime - it sounds incredible, but it's true - there are better investments (in dROI terms). Look to next week - in particular for starbonds that will be dropping big movies from their TAGs, and consequently dropping in value. And also look at starbonds attached to big budget movies released last weekend, and this coming one. Invest in those first, and if you have money left over then great, buy RBHAL. And if you don't, wait 6 days for your first profits from these investments and then buy RBHAL.
The risk here is that RBHAL may go up in price over the next few days. But if you look at the price chart on the starbond page - click on the chart and then drag to get a close-up view - you can see that the starbond had a big uptick in price after her last adjust, but this growth has tapered off the last couple of days, so it's not a huge risk. What this means is that all the regular traders who follow HSX closely and a lot of casual traders (who check in less often - like, on Fridays and adjust days) have bought it already. Future price growth will come from the casual traders who haven't checked in in a while, and small traders who are chasing the most profitable investments. From this, I'd expect it to go up in price by a little in six days, but not by a lot.
Also, if you're keen on long-term investments that pay off big, there's an even bigger adjust for an even cheaper starbond attached to another superhero movie coming out in June.